When getting CPUs' information, it assumes that CPU indexes
are not contiguous. But for ppc64 platform, CPU indexes are not
contiguous because SMT is needed to be disabled, so CPU information
is not right on ppc64 and vpuinfo, vcpupin can't work corretly.

This patch is to remove the assumption to be compatible with ppc64.

Test:
   4 vcpus are assigned to one VM and execute vcpuinfo command.

   Without patch: There is only one vcpu informaion can be listed.
   With patch: All vcpus' information can be listed correctly.
Signed-off-by: NLi Zhang <zhlcindy@linux.vnet.ibm.com>